How many children have autism?

Autism spectrum disorder (ASD) affects how a child communicates, interacts socially, and processes the world around them. But just how common is autism today? Whether you’re searching for early information, wondering about next steps, or simply want to learn more, this guide will walk you through how many children have autism, what autism is, how early it can be diagnosed, and what to do if you’re concerned.

What is autism spectrum disorder (ASD)?

Autism spectrum disorder is a neurodevelopmental condition that can affect a child’s ability to communicate, socialize, and engage with the world in typical ways. Some children with autism may be nonverbal and need more support. Others may speak fluently but struggle with social cues or sensory sensitivities. Because autism can look very different from one child to another, it’s called a “spectrum.”

Signs of autism in children

Parents are often the first to notice signs of autism. These signs can appear as early as 12 to 18 months and may include:

• Limited eye contact
• Delayed speech or lack of gestures (like pointing or waving)
• Little interest in peers or pretend play
• Repetitive movements (such as hand-flapping or rocking)
• Strong attachment to routines
• Sensory sensitivities (covering ears, refusing certain textures)

Not all children with these signs have autism, but if you notice some of them, trust your instincts. You can use screeners like the M-CHAT-R or CAST to check if your child may be at higher risk for autism. Talking with your pediatrician is also a good next step.

Autism in boys vs. Autism in girls

Autism is more than three times as common in boys as in girls. Data from the CDC shows autism rates as high as 1 in 20 boys and 1 in 70 girls.¹ Yet many girls are still underdiagnosed or diagnosed later in life.

Why is this? A review of more than 20 studies found that autism often looks different in girls. They may mask symptoms by copying peers, show fewer repetitive behaviors, or appear shy rather than socially struggling.²

Because of this, girls with autism may not be identified until school age or later. If you have concerns about your daughter’s development, even if she just seems quiet or shy, it’s worth seeking an evaluation.

How common is autism in children?

In the United States, about 1 in 31 children has been identified with autism spectrum disorder, according to 2025 data from the Centers for Disease Control and Prevention (CDC) Autism and Developmental Disabilities Monitoring (ADDM) Network.¹ This is the highest rate reported since tracking began.

Here’s how the ADDM Network has reported autism rates over time:

• 1 in 150 in 2000
• 1 in 88 in 2008
• 1 in 54 in 2016
• 1 in 36 in 2020
• 1 in 31 in 2022 (reported in 2025) ³

Why are more children being diagnosed? These numbers don’t mean more children are developing autism. It means more children are being recognized and getting the support they need. The CDC looks at 8-year-olds because most diagnoses happen by this age, which gives researchers the best picture of how common autism really is.

How many children have autism globally?

The World Health Organization (WHO) estimates that about 1 in 100 children worldwide has autism.⁴ However, this number may actually be lower than the true rate.

Autism looks more common in some countries than others, but that’s mostly because of differences in access to diagnosis. In higher-income countries like the United States, more children are diagnosed because doctors regularly screen for autism and families have better access to specialists. In many lower- and middle-income countries, autism may go undiagnosed due to fewer resources, cultural stigma, or a lack of screening tools.

How early can autism be diagnosed?

Autism can be reliably diagnosed by age 2. Pediatricians usually screen for autism at 18- and 24-month checkups. In some cases, signs may appear as early as 12 months.

How is autism diagnosed?

Autism is diagnosed by pediatric providers such as pediatricians, developmental pediatricians, psychologists, and neurologists. Various sources of information are collected to determine if a child meets diagnostic criteria, such as observation, parent report, screeners, and autism specific tests. 

The process often includes:

1. Developmental screening

At well-child visits, pediatricians may use questionnaires like the M-CHAT-R at 18 and 24 months to identify potential red flags for autism.

2. Comprehensive autism evaluation

If screening suggests signs of autism, your child may be referred for a full diagnostic evaluation. This may include:

• Autism specific tools, like the ADOS-2 and CARS, are two commonly used tests to help evaluate for autism. 
• Parent interviews and questionnaires about developmental history.
• Direct observation of communication, play, and social interaction.

3. Multidisciplinary input (if needed)

In some cases, autism assessments may include input from speech-language pathologists, occupational therapists, or educators, particularly if multiple areas of development are impacted.

What to do if you suspect autism

If you’re noticing signs of autism in your child, here are some steps you can take:

1. Talk to your pediatrician: Ask for a developmental screening or a referral for further testing.
   
2. Schedule a formal autism evaluation: At Action Behavior Centers, we offer ADOS-2 assessments for pediatric medical providers, as well as initial diagnostic evaluations by psychologists in some states.
   
3. Explore ABA therapy: Applied behavior analysis (ABA) therapy is an evidence-based approach that helps children build skills in communication, social interaction, school readiness, and daily living.
   
4. Trust your instincts: You know your child best. If something doesn’t feel right, it’s okay to speak up and advocate for your child.

How ABA therapy helps children with autism

Applied behavior analysis (ABA) therapy is a leading treatment for children diagnosed with autism, emphasizing the development of practical skills in communication, social interaction, daily living, and school readiness. It also helps children learn appropriate and safe ways to express their needs and reduce behaviors that can make learning harder.

At Action Behavior Centers, we measure the outcomes of our therapy to ensure children are making meaningful progress. Research shows that early and intensive ABA therapy can significantly reduce unsafe behaviors in children with autism.⁵ Most progress happens in the first year, and improvements continue even as therapy hours decrease.

For families, this means children are safer, stress at home is reduced, and there are more opportunities for success in school and life.

Get started with ABA therapy for autism

From your first question to your child’s next milestone, we’re here for you. Find an ABA therapy center near you today to get started.